I don't know if fox will eat corals...I'm thinking I have heard stories about it but ma unsure. Peppermints have been known to eat polyps so IDK if they could possible eat a shroom as well. Did they just disapear or waste away?
I agree with this!could be a slew of different things; water parameter issue, lighting problem, predation (from an invert or a fish), etc. Unless you witness predation, I surely wouldnt assume it, but I have heard of rabbitfish eating softies.